<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org"  
      xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
<head>
    <meta charset="UTF-8"/>
    <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
    <meta http-equiv="X-UA-Compatible" content="ie=edge"/>
    <title>login</title>
</head>
<body>
  	错误信息：<h4 th:text="${msg}"></h4>  
	<form action="" method="post">  
	    <p>账号：<input type="text" name="username" value="admin"/></p>  
	    <p>密码：<input type="text" name="password" value="123456"/></p>  
	    <p><input type="submit" value="登录"/></p>  
	</form>  
</body>
</html>